Attack on Titan is pretty rad and begs to be translated into an RPG. The following is my attempt to translate the best parts of the show into something simple that can be used at the table.
(I'm only about half way though the show, so I might be missing something especially cool. Also, this hack is based around
Castles & Crusades, but it should be basic enough to work with most D&D flavors. The armor class for the titans is descending with ascending in parenthesis.)
TITAN
NO. ENCOUNTERED: 1 - 10
SIZE: Ranges from Large to Fucking Gigantic
MOVE: 40 ft.
HD: 9
AC: -2 / -6 (17 / 21)
ATTACKS 1 Grab, see below
SPECIAL: Fear Aura, Regeneration
SAVES: P
INT: Animal
ALIGNMENT: Neutral Evil
TYPE: Titan
TREASURE: None
XP: 600+9
Titans are gigantic, naked and genital-less humanoid creatures who only exist to devour human beings. They range is height from 10 to 50 feet. The do not appear to have any motivation other than the consumption of human beings, which they do not require for food. It is speculated that titans gain nourishment from the sun. Upon death the titan's body dissolves into nothing, making it nearly impossible to study the creatures.
Titans are have extremely fast reflexes regardless of their size. If an attack roll against a fails, the attacker must make an immediate Dexterity-based saving throw. If the saving throw fails, the attacker is grabbed and consumed. The titan's grab attack also results in immediate death if successful.
Titans can only be killed by attacking the back of the neck. A titan's default Armor Class is -2 (17), but attacks to the back of the neck must beat an Armor Class of -6 (21). Essentially this is a called shot. Any attack to the back of the neck with a damage roll of 5 or better immediately kills the titan.
Attacks to other parts of the titan's body is essentially useless due to the creature's extreme regenerative capabilities. The titan regains 2d8 hit points per round. Titans that are reduced to 0 hp are unable to act for two turns while their bodies regenerate.
Titans are incredibly unsettling and grotesque monstrosities. Anyone character who has never encounter a titan before must make a save vs fear or be paralyzed. The character makes this check every round until passing the check, at which point the character can immediately act.
(This titan is 75% a re-skinned hill giant and only represents the standard grinning naked zombie variety. Other giants could work for the unique variant titans.)
Vertical Maneuvering Equipment
In order to reach the vulnerable spot on a titan's body, human beings have developed a technology that allows them to move quickly and gracefully around the hulking behemoths. This technology includes a harness with two pneumatic grappling hooks and a boosting mechanism to achieve momentum. Soldiers typically wield two swords with exchangeable blades to insure a deep cut into the titan's neck.
When using a vertical maneuvering harness, a character can move 80 ft per round, plus 10 ft for each point of their Dexterity modifier. For example, a character with a +2 Dex modifier can move 100 ft per round.
Due to the extremely high speeds of the vertical maneuvering system, it imparts an armor class bonus of +10. A harness cannot be used with any armor heavier than leather.
If a character is not actively using the system (i.e. standing on the ground), the armor class bonus and movement rate are negated.
One proven technique for combating titans with the vertical maneuvering system is flanking and distracting the target while one character goes in for the attack. For every character in range of a titan's grab, the attacker gains a +2 bonus to their To Hit roll.
While I like to avoid grids and miniatures, this would be a good time to use a grid for strategic combat, especially to help calculate the flanking bonuses and the disparity in the movement rates between PC and titans.
Please note that none of this has been play-tested and I'm just going off what would feel right to emulate the show in D&D. If you see any glaring mistakes or if you think my math is all screwy, let me know.
